The Truth About Sharks and Fishing

23 Feb 2009

Sharks are one of the greatest mysteries of the world today. We probably know more about the moon then we do about sharks. This is primarily caused by the fact that as a group sharks are as varied as people are. For instance, the white shark, commonly known as the great white shark, travels thousands of miles every year. A single great white shark can encircle the globe hundreds of times in its lifetime.

Shark attacks are exploratory bites. This is the shark's only method of getting a feel for things. These bites are no different than when a dog mouths something in order to get a feel for what that thing is. The biggest difference is that sharks have rows and rows of razor sharp teeth. The problem with calling these encounters "attacks" is that if a shark was attacking a person, that person would be dead.
The image of sharks as human killing machines is wrong. Sharks may not be the gentlest creatures in the sea; they are after all one of the greatest predators in the oceans and arguably on of the greatest predators the world has ever seen but they are not indiscriminate in their killing. They use a natural process to help them select the prey that will give them the biggest caloric gain for the effort they have to put forth. They are smart hunters. They would rather spend their time hunting easy to kill, fat animals then something that is easy to kill and mostly muscle.
Shark "attacks" against humans are usually the result of mistaken identity. Surfers, the most commonly "attacked" human, look a lot like a seal from the bottom. A shark will come up from below in its normal attack pattern and bite the surfer. Typically, it immediately releases the surfer, shocked that it is not a seal and swims away. Why would a predator eat an athletic human that has very little fat content compared to a seal that is covered in blubber? The energy that a shark would exert to kill and eat a human would make the caloric gain worthless. That same effort could be spent hunting and killing a creature that would actually have a benefit to the shark.
Another thing to consider is the actual chance that something will happen. According to the Florida Museum of Natural History, from 1954 to 1994 in the United States, coastal areas have seen 6,470 lightning strikes of which 1,618 have been fatal. Compare this to shark attacks during this same period 412 attacks with 17 being fatal ("A Comparison"). These "attacks" happen less often than a person getting struck by lightning. This means if someone is going to worry about going somewhere, it would make more sense to worry about going outside and not worry about getting into the ocean. Keep in mind that if a person gets struck by lightning, that person will most likely experience some brain damage as well as a physical injury, possibly death. Shark attacks rarely end in death and if basic first aid is administered, it should prevent death by shark bite.
The movie Jaws scares the bejeezus out of a lot of people. The idea that there is something on this planet that could potentially kill a person so quickly and easily is a very common fear. Unfortunately, there are a large number of falsities in this image of sharks. For starters, the largest sharks are always females, yet the monster shark in the movie was a male. Also the sheer size of the Jaws shark was off the charts. Sharks, especially white sharks, can get quite large but the size of the one in the movie is impossible even for such an amazing fish to achieve. The part of Jaws that is the biggest myth is that a shark would hunt a person. Sharks, like most predators, are lazy and want the big payoff at the end of a kill. These discriminating killers are being wiped out by one of the most indiscriminate killers on earth: human beings.
One of the ways that sharks are caught before being divested of their fins is through a process called long-line fishing. This is the process of laying out up to 20 miles of line with baited hooks behind a boat and dragging it through the ocean catching anything and everything. Since sharks are such an efficient creature, they have very little decent meat compared to a tuna fish. When sharks are brought onto a boat they have their dorsal, pectoral and tail fins cut off and are tossed right back into the water. Sharks, unlike most fish, have to keep moving in order for water to move across their gills to produce oxygen. Without their fins they are unable to swim and they drown, much the same way a human being would drown if their arms and legs were tied before tossing them into the ocean.
Long lining would be just like someone hooking 40 miles of spiked cable to the back of his Hummer, driving through Yellowstone National Park and catching any animal it came into contact with. While going through the catch he would take any wolf or mountain lion, cut off its legs and then drop it back off into the forest, leaving it to bleed to death in its natural habitat.
This type of fishing is targeting tuna fish and other large species of fish that are the prey of sharks. What typically happens is that a shark will see the tuna floating aimlessly in the water above it. The shark will sneak up from below and bite the tuna getting itself stuck on the hook. All sharks caught by long lines are considered by-catch, which means they are the unwanted by product of an environmentally destructive fishing practice.
Another method of fishing that is detrimental to shark populations is drift nets. Drift nets are huge nets that are left for the day or week to drift in the ocean catching whatever they can. When they are picked up and opened on the deck, the fishermen go through and divide the catch up. Any sharks that are found are immediately relieved of their fins and tossed back into the water.
The process in which the fins are removed is possibly the most objectionable part of the whole process. Imagine a cow being caught, dragged to the ground and slaughtered while they mooed loudly. After all the meat was removed, the cows would be left to bleed to death on the very grass the cow grazed upon. As disgusting and immoral as this sounds, the de-finning of sharks happens in a very similar manner. What is worse for sharks is that they are not even a planned catch. They just happened to pop up on one of the hooks or in the nets. Rather then let them go, the fishermen remove the only part of value and toss the rest into the ocean to die.
Another problem with long lining and drift net fishing is that they also lead to the overfishing of certain prey species leading the predators to seek different prey in larger numbers. It was discovered in the arctic that seals numbers were declining even though there was a ban on seal hunting. What was happening was that as more and more of the fish that were common prey of the larger predators were caught, the predators were forced to eat more and more seals. The overconsumption of these prey species can cause the same imbalance withing the smaller predator prey relationship that seals have with smaller fish and plants.

Continued next Monday, in the mean time please check out this website__. He shares a lot of my concerns as well as has some interesting comments on the state of the underwater world.